\subsection{Navigation}
We have chosen to implement a breadcrumbs navigation because it makes sense when working with geographical data. When starting the application, it presents a list of continents to choose from. When a continent has been chosen, a list of countries appears, which can be chosen from. When a country is chosen a list of cities in that country appear. A breadcrumb is added at each step of selection, for example at the root, the breadcrumb trail would look like this: \textit{Home/}. When the continent Europe is chosen the breadcrumb trail would look like this: \textit{Home/Europe/}. And finally if Denmark is chosen as country in Europe, the breadcrumb trail would finally look like this: \textit{Home/Europe/Denmark}, and the page would display a list of cities in Denmark. 